Fig. 1: MoCel12A/B are required for the pathogenesis of M. oryzae.
a MoCel12A and MoCel12B transcription levels in different tissue or during M. oryzae infection in rice. The fungi were grown in CM media, and the mycelium and spores were collected for RT-qPCR assays. The rice leaves were inoculated with M. oryzae spores at a concentration of 1 × 105 per ml. The leaves were sampled at indicated time points for RT-qPCR assays. The M. oryzae MoActin was used as a reference gene. hpi, hours post inoculation. Values are means ± SD (n = 3 biological replicates). b The hydrolytic activity on β-glucan (left panel) and xyloglucan (right panel) of recombinant MoCel12 endoglucanases. MoCel12A (E153D) and MoCel12A (E238D) are the mutated MoCel12A. c Knocking out of MoCel12A did not impair the virulence of M. oryzae. Left, disease symptoms of rice leaves infected with Guy11 and two ΔMoCel12A mutants. Conidial suspensions (1 × 105 conidia per ml in 0.02% Tween-20) were sprayed onto the leaf surfaces of 2-week-old rice seedlings. Images were taken at 5 dpi. Bar = 1 cm. Right, the relative fungal biomass was determined by qPCR for the M. oryzae Pot2 gene against rice OsUbi gene. Values are means ± SD (n = 3 biological replicates). d M. oryzae ΔMoCel12A/B double mutant exhibited enhanced virulence on rice. Left, disease symptoms of rice leaves infected with Guy11 and two ΔMoCel12A/B mutants. Right, relative fungal biomass. Others are as in (c). e Overexpression of MoCel12A in M. oryzae reduced the virulence on rice. Left, disease symptoms of rice leaves infected with Guy11, Guy11-GFP, and two independent MoCel12A overexpression strains. Right, relative fungal biomass. Others are as in (c). * and ** indicate significant differences from the treatment of Guy11 at P < 0.05 and 0.01, respectively (two-sided Student’s t test).
